Former media mogul Conrad Black gives a speech at a business luncheon in Toronto, June 22, 2012.Mark Blinch

TORONTO (Reuters) - Former media mogul and convicted felon Conrad Black may no longer hold executive positions at listed companies or investment funds in the Canadian province of Ontario, the country's premier securities regulator ruled on Friday.

Black brushed off the ban as "the comparatively inoffensive end of more than 11 years of persecution" and said the regulator was to blame for the downfall of his media company.

The Ontario Securities Commission imposed the same penalty on his former business partner, John Boultbee, after a lengthy process that was delayed by U.S. legal proceedings against both men. Three other executives of Black's former media company, Hollinger Inc, settled earlier with the OSC.

"The OSC destroyed Hollinger Inc and vaporized the shareholders' interest and enriched a gang of charlatan corporate activists when it denied our effort to privatize it in 2005," Black said via a spokesman in response to the ruling.

Through Hollinger, Black once ran an international newspaper empire that included the Chicago Sun-Times, Britain's Daily Telegraph and the Jerusalem Post as well as extensive holdings in Canada, but he ended up in U.S. prison for fraud.

He was found guilty in the United States in 2007 of scheming to siphon off millions of dollars from the sale of newspapers owned by Hollinger, where he was chief executive and chairman.

Two of his three fraud convictions were later voided, and his sentence was shortened. He was released in May 2012 after more than three years in prison.

The OSC based its ruling on the U.S. criminal conviction.

The ban covers publicly traded and private companies that issue or trade securities in Ontario, home to the financial hub of Toronto.

After his release from U.S. prison, Black returned to Canada, where he writes opinion pieces in the National Post newspaper, which his company once owned.